n.1. often Sun The star around which Earth and other planets orbit. It provides heat and light to Earth. It has a mean distance from Earth of about 150 million kilometers (93 million miles), a diameter of approximately 1,391,000 kilometers (864,000 miles), and a mass about 333,000 times that of Earth.
2. A star that is the center of a planetary system.
3. The radiant energy, especially heat and visible light, emitted by the sun; sunshine.
4. A sunlike object, representation, or design.
v.tr. To expose to the sun's rays, as for warming, drying, or tanning.